Mr Allemeersch managed to wrench himself from his mangled vehicle and continued his escape on foot but the tractor soon caught up with him as he hobbled round his van across the corn stubble. Once in range, the tractor's articulated arm hit the butcher with full force on the head, killing him instantly.

The farmer has been arrested and now faces charges of voluntary homicide, which carry a life sentence.

Versions of what drove Mr Boutevillain to commit such a crazed act differ.

Relations and the local mayor of Couvertpuis say the farmer felt harassed by his rival, whose wife was the butcher's accountant, that he had thrown stones at his home, threatened him with an iron bar and beeped his horn in front of his farm to provoke him.

"It obsessed him," said mayor Francis Legrand. "That could explain, without justifying it, why he lost the plot. He was normally a very reasonable, calm man involved in the community."

Relations of the victim said he merely sounded his horn to notify villagers that the meat man was in the village in the usual way.

"(Mr Boutevillain) was the one who harassed my brother," said Jean-Marc Allemeersch, who said his sibling was the victim of a "veritable ambush".

"He must have been waiting for him, and when my brother finished his delivery in Couvertpuis at 8.30pm, he deliberately scratched his van with his tractor to provoke him and lure him where he wanted."

Furious, Mr Allemeersch pursued the farmer into his field with his van to demand reparation, where the tragic events unfolded.

"He pursued my brother like a hunter his prey. His determination was total," said Mr Allemmersch.